space and place

What role does setting play in the books you read or write?
It's a bit like talking about air. Setting is vital, but just kind of there. Like air, it's got to be life-sustaining, but not too noticeable, I think, at least in crime fiction.
Setting in a book remains relatively slow-moving against the dynamics of whatever the characters are up to. It ties things together. In some books setting is more a character than others, such as heavy rains and a fast-rising river figuring...<![endif]--><!--[if gte vml 1]>